Combination directional drilling and tapping unit



Dec. 5, 1939. CREGAR 2,181,873

COMBINATION D IRECTIONAL DRILLING AND TAPPING UNIT Filed Nov. 6, 1937 r2 Sheets-Sheet 1 Dec. 5, 1939. I CREGAR 2,181,873

COMBINATION DIRECTIONAL DRTLLTNG AND TAPPING UNIT Filed Nov. 6, 1937 2Sheets-Sheet 2 Patented Dec. 5, 1939 I a COMBINATION DIRECTIONALDRILLING AND TAPPING UNIT Howard Cregar, Richmond, Ind assignor to TheNational Automatic Tool Company, Richmond, Ind., a corporation ofIndiana Application November 6, 1937, S erial No. 173,066

9 Claims. (Cl. 10-128) I It has been the conventional practice when itOne of the objects of the invention is to prohas been necessary tomachine a work piece on vide a device ofthe class described which remorethan one side, to employ a plurality of sepduces the succession ofoperations conventionally arate machines, with one or more machinesbeing required to finish a work piece. I

5 used for each side. The work piece would be Another object of theinventionjs to provide a 5 located with respect to each machine and withdevice of the class described, performing upon a respect to each sideto' be machined. In most ,work piece at one setting aplurality ofotherinstances, this entailed moving the work piece wise successiveoperations required to finish the by hand from one machine to anotherand fasworkpiece.

l0 tening the work piece upon the individual work Another object oftheinvention is to provide 1 table of each machine, while in otherinstances, a single machining unit combining andl'performthe work piecewould be mounted -on a work ing a plurality of operations upon more thanone table common to several machines which would side of a work piece.be clustered around it. Another object of the invention is to provide Inthose instances where a common work table a machining unit performing aplurality of dis- 15 was used two practices developed, one in whichtinct operations upon a work piece from different the work table wasrevolved and several work directions. pieces were fastened thereto androtated from Another object of the invention is to provide station tostation, and the other, one in which a machining unit performing aplurality of difthe table was stationary and only one piece 'was ferentoperations upon different sides of a work 20 fastened thereon. piece ata single setting thereof.

With the revolving or index type of table, the Another object of theinvention is to provide work pieces were machined on the same side by adevice of the class described, traversing towards different machines.while with the sta i n ry a work piece in one direction, and machiningthe table, the work piece was machined on different w rk piece from aplurality of directions, one 5 sides y separate m ch e In ei h cas ly ormore of which are different from-the first dione side was machined byeach machine, and ti n, additionally. the W Piece waslmachined 0nAnother object of the invention is to pmon y t se ew d s w c could bereached by vide a machining unit brought into work position mechmeswhose size and Operation by a single traversing movement and performingmitted them t0 be used in a cluster, it being a plurality of machiningoperations upon several preciated that room had to be provided also fordifierent fa e of t work the operator and also access to the work tableAnother object of t invention i t provide the Setting and removal of theWork Piecesin combination with a conveyor for work pieces, a

Consequently, it will be Observed that the machining device traversingacross the path folnumber of sides of a work piece machined at any lowedby t k piece on t conveyor and given i was limited there e alwayschining the work piece upon a face angled relasome sides left unfinishedif a work piece had tive to Said path more sides to be finished thancould be done at .vAnother object f the invention is to provide a 40 anyparticular work table This necessitated machining unit traversing intothe path followed 40' additional subsequent and successive operations. b

y a work iece when fed to or removed from the In addition to this, thosemachining operations ,machmingpdevlce and performing a machining whichcould not be performed in combination 1 operation upon the part withinthe pro ected path with other machin ng operations also required of Saidwork piece.

45 subsequent operations before the work piece was 1 completelyfinished, and the successive machinga oblject h i g z 3 3 igs:

ing operationsthus needed to finish a work piece aneous y a p i 1 p mgtimed cycles, in which several of the opera- .were greatly multipliedand the total 'of the suc- 1 cessive increments of time requiredfor thetrons having fast cycles are performed successively cessive operations,the extra labor, the expense y One machining unit approximatelywithin'the m of machines to perform the extra operations, and Cycle of aSlower Operation Performed y another the fioor space occupied by theextra machines u tbecame a large and objectionable part of the costAnother object of the invention is to provide of production encounteredin machining work a combined drill. and tap head traversed by a piecesin the conventional manner. single movement, wherein the feed of thedrill 55 Fig. 1 is a side elevation of a combined drill and tap unitillustrating a preferred embodiment of the invention;

Fig. 2 is a diagrammatical illustration of the electrical circuitsforming a part of the invention for controlling the device illustratedin Fig. 1;

Fig. 3 is a plan view of acluster of machines one of which illustratesanother embodiment of the invention;

Fig. 4 is a side elevation and projection of the apparatus illustratedin Fig. 3;

- Fig- 5 is a side elevation, partly in projection.

'- of a construction illustrating another embodiment of the invention.

Referring now to the drawings in further detail, and particularly Fig.l, a better understand ing of the invention will be had when it is observed that a drill head l0, carrying the drill 24, is mounted forhorizontal traverse upon a base l4 for movement towards and away from awork piece It. The work piece I6 is also located upon the base l4, whereit is held in place by a clamp l6 against a positioning fixture 20. 'Atap head I2 is rigidly carried by the drill head I, with a tap 26carried thereby disposed at an angle relative to the drill 24. The drillhead I0 is powered by the motor 22, and the tap 26 is powered by themotor 26.

Two sets of controls are employed for operatin the device. One of thesesets, the manual .control, is accomplished directly by means of themanual movement of the four switch buttons. mounted conveniently at handin the switch box 38, the four buttons comprising a sta button 40, astop button 42, a forward traverse button 44, and a reverse traversebutton 46. The other controls are automatic ones, comprising twonormally open contact switches 34 and 26 mounted upon a drill head andthe cam members 30 and 32, rigidly mounted in an adjustable manner uponthe base. 14, and which actuate the.

switches 34 and 36, respectively, with the trav- ,ersing movement of thedrill head I6.

An adjustable'stop-46 is carried by the drill head to contact the worksupporting block 56 when the feed of the drill 24 into the work piece I6is completed, as indicated inphantom by thenumeral 52;at which time thetap 26 isbro'ught into its work position, as indicated in phantom at 64,to start its cycle of operation. The feed of the taps may be automaticas an incident to their rotation, the mechanism for accomplishing thisresult being of the type shown in prior Patin Fig. 2 as. controlled bythe spool valve 66. The piston rod 66 is connected directly to the drillhead it for traversing the latter, while the cylinder 59, in which thepiston rod 58 is mounted, is secured relative to the base l4.

Having thus described the physical elements performing the functionsindicated, the control and operation of these elements will be betterunderstood with reference to .Fig. 2, wherein the electrical circuitswhich coordinate and control the several functions mentioned areillustrated and operated according to a predetermined pattern.,

The electrical units employed in the electrical circuits of theinvention comprise the drill motor 22 and the reversing tap motor 28,already mentioned, the latter having a forward terminal 66 and areversing terminal 62; a'magneticbrake(not shown) for the tap motor 28to prevent a reverse overrunning of the tap feed 21; manually actuatedcontact control switches comprising a normally open start switch 12controlled by the button 46; a normally losed stop switch I4 controlledby the button 4 normally open switches 16 and I6 controlled by buttons44 and 46, respectively; a relay 84 controlling four switches, 86 and 66of which are normally closed, and 90 and I60 of which arenormally open;a rotary limit switch actuator I02, which is operated by a worm gear andthread assembly I04 in direct relationship with the turning of a tap 26,and is provided with two interconnected contacts operating to closethree switches, two of which, I66 and I66, are normally closed, and thethird, I it, normally open when the tap 26 is fully retracted; a singlethrow double contact snap switch having an actuator I I2 operated byopposing solenoids l l,4and i I 6,whereby, the switch I 20 is closedwhen the solenoid 1 Benergized, and the switch 122 is closed alternatelytherewith when the solenoid I I6 is energized; and 4 main power lines 64and 66, which are represented diagrammatically by a square symbol 66 anda Referring more particularly to the automatically controlled mechanicalunits employed in 45 connection with the electrical circuits, namely,the normally open switches 24 and 36 already described, these switchesare closed when their contact arms are raised by the cam members 30 and32, respectively. The switch 34 is closed by the cam member 30 when thedrill head is in its fully retracted position and opens when the forwardtraverse is commenced. The switch 36 is normally open, and is closedby'the cam member 22 when the drill feed is completed and the adjustable stop 46 contacts the work support 66.: Before describing theelectrical circuits involved. it may be well to point out the preferredpattern according to which the invention illustrated isv operated. a

The drill motor is first started. This rotates the drill 24 and developsoil pressure for moving the piston rod 56. Thereafter, the forwardtraverse button is pressed and the drill head advanced at a rapidtraverse until the work sta- '66 I tion'of the drill is reached,whereupon the drill head forward traverse is cut to a drill feedrat'e.The means for traversing and feeding the drills may be of any well knowntype, such as shown ground symbol 10, respectively.

in Patent No, 2,108,779. When the drilling op-vo' erationis completed,the forward rotation of the tap 26 is commenced, fed into the work andreversed. After reversal and withdrawal of the tap is completed, thedrill head is automatically returned to its start position at a rapidreverse 15 traverse all the way, the reverse rotation of the tap motorhaving ceased the instant the tap cleared the work.

When it is desired to start the drill motor 22,

\ the normally open start switch 12 is temporarily closed. Thiscompletes a circuit commencing at the power line terminal 68a andincludes the normally closed stop switch I4, relay I44, the drill motor22, the overload switch I46, and terminates at the ground terminal a.The relay I44 is energized simultaneously with the drill motor 22, andwith the closingof the relay switch M411 2. self-sustaining circuit iscompleted, exclusive of the start switch 12. circuit is one starting atthe terminal 68a and extends through the normally closed stop switch I4,the relay switch I44a, which is now closed by the solenoid I44, thesolenoid-I44, the drill motor 22, the overload switch I46, andterminates at the ground terminal 10a.

With the drill motor running and the oil pressure built up thereby, theforward traverse button 44 is pressed, closing the switch 16. Due to thefact that the automatic switch 24 is now closed by the cam member 30,this completes a circuit starting at the terminal 68b and runningthrough the now manually closed switch I6, line 16b, the now closedautomatic switch 34, line 34b, and through the solenoids 80 and H4 tothe ground terminal 10b. With the energization of the solenoid 80, thespool valve 60 is drawn to forward position, a position opposite tothatillustrated in Fig. 2, and a hydraulic flow of oil under pressure isdirected to the rear side I48 of the traversing piston I50. The solenoidI I4 draws a snap switch to the position illustrated in Fig. 2 wherebythe switch I22 is open to prevent energization of the spool valvereversing solenoid 82, and the switch I20 is closed as one of two openlinks, the other of which is the automatic switch 36,

whereby the forward circuit of the tap motor 28 is made ready for thetime when the automatic switch 36 is closed.

Thereafter, the piston I50 is driven'hydraulically forward at a rapidtraverse until such time as the drill 24 is brought into its workposition, whereupon the forward traverse -of the drill head is reducedto the feed rate of the drill 24 in a well-known manner. When the drillfeed is'completed, the stop 48 comes in contact with the work support 50 and simultaneously therewith the automatic switch 36 is closed .by thecam member 32. This completes the circuit, of which the automatic switch36 was the last link, and starts the forward turning of the tap motor28.

The circuit starts at the terminal 88b, and includes in series, line36a, switch 36, line 3617, closed snap switch I20, line I06a, closedswitch I08 of the rotary limit switch actuator I02, line I06b, thesolenoid of the relay 84, line 8412, the

forward winding of the tap motor 28, the overready described, to theterminal 100, including the forward winding of the tap motor 28.

Simultaneous with the closing of the switch I00, normally open switch 90of the relay 84 is also closed, which completes a circuit partly inshunt with the sustaining circuit just described. which leads from thesustaining circuit beyond This sustainin the switch I06 and runs throughline 80a, now closed switch 90, line 90b, solenoid II8, line H812 topole 100. When the solenoid H8 is energized, which for all practicalpurposes happens immediately after the forward traverse button 44 ispressed, the snap switch I I 2 is snapped over, opening switch I 20 ofthe forward traverseinitiating circuit, and closing switch I22, whichcompletes one of three links in the spool valve solenoid reversingcircuit, of which the other two links are the now open relay switch 86and the now closed time limit switch I08. Since the normally closedswitch 86 is now open, this obviously prevents any possibility of thespool valve reversing solenoid 82 being energized in anyway at thistime, and the normally closed switch 88 of the relay is also opened toprevent any energizing of the reverse winding of the tap motor 28.

The forward rotation of the tap motor 28 started by the closing of the;snap switch I20 and sustained by the sustaining circuit involving thenow closed relay switch I00 continues until such time as the rotarylimitswitch is snapped to its alternate position, the latter takingplace when the tap feed is completed. When .the rotary limit switchreverses its position, switches I06 and I08 are opened and switch IIOclosed. When the switch I06 is opened, the sus taining circuit throughthe relay 84 and the forward winding of the tap motor 28 is broken andthe relay switches 86, 88, 90 and I00 reassume their positions, asillustrated in Fig. 2, the relay solenoid 84 being de-energized. Withthe opening of the rotary limit switch I08, the circuit including thenow closed snap'switch I22, and the closed relay switch 86, is kept openin a way preventing the spool valve reversing solenoid from beingenergized. This obviates any danger of a reverse traverse while the tap26 is still in the work piece I6. I

The forward turning of the tap motor 28 having been stopped, the closingof the rotary limit switch IIO completes a circuit through the reversewinding of the tap motor. This circuit commences at the pole 68d, runsthrough the now closed switch IIO, line IIOb, closed relay switch 68,line 88b, the reverse winding of the tap motor 26, the overload switchI52, and terminates at the pole 100. This starts the reverse movementandwithdrawal of the tap 26 from the work piece I6, which will continueuntil the rotary limit switch is again thrown into the positiondisclosed in Fig. 2.

When this takes place, this indicates that the tap 26 is free of thework piece I6, and the reverse traverse of the drill head may becommenced. With the return of the rotary limit switch to the positionshown in Fig. 2, the switch I08 is closed as the last open link nowexisting in the circuit energizing the spool valve reverse solenoid 82.This circuit commences at the terminal 68d, runs through th closedswitch I08. line I'08b, now closed switch I22, line I22b; closed relayswitch 86, line 86b, solenoid 82,'and ends at the ground terminal 10d.Thereupon the spool valve 60 is drawn towards the solenoid 82 and the,hydraulic pressure fed to the'forwar'd side I54 of the cylinder to bringabout a rapid reverse traverse of the drill head to its startingposition, In which-the auto atic switch is again closed by the cammember; 0 preparatory toa repeat of the cycle just described whenevervthe forward traverse button is again pressed.

For the sake of simplicity, the safety devices have been omittedfrom'the circuits illustrated in Fig. 2, and for the same reason thecontrol circuits for the drill and tap motors have been illustrated asrunning directly to the motor, rather lo isr illustrated, wherein thedrill and tap units I68 and I62, respectively, are contained in aninto-.- gral housing and disposed side by side in a horizontal plane,rather than in a vertical plane as illustrated in Fig. 1. The unit thusprovided is associated at one station of a rotary work table I66, whichhas therearound three other stations, one of which, I68, is for theoperator, another, I18, is for a machining unit, I12, and the third,I14, is for a machining unit, I16. The work pieces illustrated in Figs.3 and 4, comprise internal combustion engine blocks I18, which are to bemachined upon more than one side.

In this particular embodiment, it will be observed that thedrills I88operate in a direction radial to the revolving work table I66 and nor-.

ing to the'operating time of the several units.

clustered around the work table I66, since the taps I82 are combinedtooperate with the drills I88 in an overall cycle not to exceed one of theapproximate operating time cycles of either or both of the other unitsI12 and I16.

Referring to Fig. 5, it will be observed that a three-directionalmachining operation is performed upon a work piece- I84. This work pieceis a V-8 block for an internal combustion engine requiring machiningoperations upon a plurality of sides. In this particular embodiment,taps I86 and I88 machine the end I98 and face I92, respectively, of theblock I84, while the drills I94 operate into the side I96 of the block.The tap's I86, the taps- I88, and the drills I94 are all angled, eachrelative to the others, and this particular modification is employed toprocess engine blocks carried end to end in a spaced relation along astraight line conveyor although it may be used to servein connectionwith a revolving'work table.

The traversing movement of the drill head I98 projects the tap head 288,carrying the taps I86 into the path traversed by the block I84 upon theconveyor, and from this position they machine the end I98 thereof withinthe projection of the path followed by the block I84 upon the conveyor.

This particular embodiment obviates the need for the subsequent handlingof each block, in

.which the block would have .to be turned crosswise of the conveyor andfed into or between an? other set of machines to finish the ends I98thereof. I

With this that a three-directional combination drill and tap unitsimilar to that shown in Fig. 5 could be employed with equal successupon the other side of the block "(and operations fog-Bail sidesperformed-"thereon at one settingfandat' one time,

, whereas conventionally a large number of settings and a much longerand costlier product on embodiment, it will be appreciated.

schedule would be required to finish the work piece.

In this way it will be observed that the invention provides an improvedmethod for finishing work pieces, and, in addition to the expressedobjects, a machining unit performing a plurality of distinct operationsis provided, either to work alone, or in'cooperation with others, tomachine a work piece upon more than one side, some of which areotherwise inaccessible with conventional practices. Additionally, asaving in time, labor, machines and floor space is accomplished, and theinvention eliminatesmany discrepancies arising out of numerous settingsof a work piece upon different fixtures. Moreover, the inventionprovides machining units performing a plurality of operations upon awork piece independent of ,and free from any space restrictions orconveyor requirements normally encountered in machining a work piece;

Consequently, although preferred embodiments of the invention have beenshown and described therein, it will be apparent to those skilled in theart that various uses, modifications and changes may be made thereinwithout departing from the spirit and substance of the invention, thescope of which is commensurate with the appended claims.

What I claim is: l

1. In a. unit of the class described, a work table, a drilling mechanismmovable to and from said table for machining operations, a tap mechanismcarried by said drilling mechanism and traversed with said drillingmechanism, means for feeding said drilling mechanism relative to saidtable and indexing'said tap mechanism, and means for feeding said tapmechanism independ ently of said drill feeding means.

2. In a unit of the class described performing a v plurality ofmachining operations in different directions, a machine tool and drivefor each operation mounted one upon another, means for rapid traversingsaid machine toois together as a unit relative to work piece and feedingone of said tools in its operation to a position indexing another ofsaid tools, and means for feeding the last-named tool successively andindependently of the first fed tool.

. 3. In a unit of the class described, a work table, a drillingmechanism movable to'ands from said table for machining operations, atap mechanism carried by said drilling mechanism at an angle thereto andtraversed with said drilling mechanism, means for feeding said drillingmechanism relative to said table, and means for feeding and reversingsaid tap mechanism independently 'of said drill feeding means.

4. In a machine tool of combinedunits carried by one another andperforming a-plurality of machining operations having diiferent feedcharacteristics of which the respective lines of feed are angled onetoanother, .means' for traversing said unitssimultaneously alongone ofsaid lines of feed and feeding the unit'having said line of feed, meansfor positioning said unit at the end" of said feed for indexing anotherof said-units, separate means for controlling and feeding said lastunitto the completion of the 'workz'cycle thereof, and means for reversetraversing said units simultaneously.

5. In" a unit-of the class described having a work table, a machiningmechanism traversable relative to said work table, a. second machiningmechanism rigidly carried by said first mechanism and traversablesimultaneously therewith,

pendently according to a predetermined pattern Y of operation in whichthe feed movement of one chining operation upon a work piece on saidtable,

a second machine tool unit rigidly: carried by said first tool unit forperforming a second machining operation upon the same Work piece in adirection angled to said first direction, means poi sitioning said firstmeans at a predetermined point of said traverse for indexing said secondtool, and automatic control means for initiatin the operation of saidsecond machine tool unit upon the indexing thereof.

'7. In a device of the class described a work table, a machine toolunit, power driven means for rapid traversing and feeding said table andunit relative to each other in a given direction to perform a machiningoperation upon a work piece on said table, means carried by. saidmachine tool unit for performing a second machining operation upon thesame work piece in a direction angled to said first direction, andauto-' matic control means for indexing and initiating the operation ofsaid carried means at a predetermined point of said feed of said machinetool unit.

8. A machine tool comprising a work table, a tool unit, hydraulic meansfor traversing said table and unit relative to each other through arapid forward, feed forward and rapid reverse traverse cycle to performa machining operation upon a work piece on said work table, a secondtool unit carried by said first tool unit for performing a machiningoperation upon the same work. piece, stop means for positioning saidfirst unit prior to said reverse traverse to index said second toolunit, interlocking control means actuated upon said indexing forinitiating operation of said second tool unit through a machining cycleand means actuated upon the finish of said last machining cycle foreflecting operation of said hydraulic means to accomplish said rapidreverse traverse.

9; A machine tool comprising a work table, a tool unit, means fortraversing said table and unit relative to each other in given directiontap head carried by said tool unit, a reversing motor and mechanism fordriving said head, means for positioning said tool unit at the end ofsaid feed movement to index said tap head, electrical interlockingcircuits for maintaining said indexing position and'controlling theoperation of said reversing motor including a control responsive to theindexing of said tap head for effecting a forward running of said motor,a rotary limit device operative to stop said forward running of saidmotorat a predetermined pointand efiect a reversal of said motor, andmeans controlled by said'rotary limit device for traversing said tableand tool unit in a direction opposite said first direction.

HOWARD CREGAR.

- through a motion including a feed movement, a

